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301.
Marcus W. McGinnis Zachary M. Parker Nicholas E. Walter Alex C. Rutkovsky Claudia Cartaya-Marin & Ece Karatan 《FEMS microbiology letters》2009,299(2):166-174
Vibrio cholerae , the causative agent of the devastating diarrheal disease cholera, can form biofilms on diverse biotic and abiotic surfaces. Biofilm formation is important for the survival of this organism both in its natural environment and in the human host. Development of V. cholerae biofilms are regulated by complex regulatory networks that respond to environmental signals. One of these signals, norspermidine, is a polyamine that enhances biofilm formation via the NspS/MbaA signaling system. In this work, we have investigated the role of the polyamine spermidine in regulating biofilm formation in V. cholerae . We show that spermidine import requires PotD1, an ortholog of the periplasmic substrate-binding protein of the spermidine transport system in Escherichia coli . We also show that deletion of the potD1 gene results in a significant increase in biofilm formation. We hypothesize that spermidine imported into the cell hinders biofilm formation. Exogenous spermidine further reduces biofilm formation in a PotD1-independent, but NspS/MbaA-dependent, manner. Our results suggest that polyamines affect biofilm formation in V. cholerae via multiple pathways involving both transport and signaling networks. 相似文献
302.
303.
J F McGinnis 《Biochemical and biophysical research communications》1983,116(2):689-695
The major form of glycerol phosphate dehydrogenase in human heart (GPDH-1) is a minor form (less than 15%) in brain and other tissues and is extremely labile. After GPDH-1 was eluted from an agarose column to which Cibacron blue F3GA had been covalently linked, (a) it was no longer labile (t 1/2 at 40 degrees C changed from 1.6 min to greater than 180 min); (b) it could now be stained for activity on native gels following electro-phoresis; and (c) it now migrated with the bromphenol blue dye front. The results suggest that this stabilized form of GPDH-1 is due to the covalent binding of charged ligands from the column and that this technique may be useful for studying the molecular structure and/or the active site of GPHD-1 and possibly of other enzymes which bind to blue agarose. 相似文献
304.
This article is part of a Special Issue “Puberty and Adolescence”. 相似文献
305.
Rachel Dyer Yuanli Song Jie Chen Elizabeth Bigelow Jennifer McGinnis Lauren Jenkins Sanchayita Ghose Zheng Jian Li 《Biotechnology progress》2020,36(6):e3057
Viral safety is required for biological products to treat human diseases, and the burden of inactivation and or virus removal lies on the downstream purification process. Minute virus of mice (MVM) is a nonenveloped parvovirus commonly used as the worst-case model virus in validation studies because of its small size and high chemical stability. In this study, we investigated the use of MVM-mock virus particle (MVP) and bacteriophage ΦX174 as surrogates for MVM to mimic viral clearance studies, with a focus on chromatography operations. Based on structural models and comparison of log reduction value among MVM, MVP, and ΦX174, it was demonstrated that MVP can be used as a noninfectious surrogate to assess viral clearance during process development in multiple chromatography systems in a biosafety level one (BSL-1) laboratory. Protein A (ProA) chromatography was investigated to strategically assess the impact of the resin, impurities, and the monoclonal antibody product on virus removal. 相似文献